Correct minor typos on landing page

Author: rshah713

index.html

@@ -126,7 +126,7 @@ <h2>CircuitPython is based on Python</h2>
         and universities. It's a high-level programming language which means it's
         designed to be easier to read, write and maintain. It supports modules and
         packages which means it's easy to reuse your code for other projects. It
-        has a built in interpreter which means there are no extra steps, like
+        has a built-in interpreter which means there are no extra steps, like
         compiling, to get your code to work. And of course, Python is Open Source
         Software which means it's free for anyone to use, modify or improve upon.
       </p>
@@ -154,11 +154,11 @@ <h2>CircuitPython is based on Python</h2>
            srcset="{{ "/assets/images/raspberry_pi.png" | relative_url }} 1x,
                    {{ "/assets/images/raspberry_pi@2x.png" | relative_url }} 2x,
                    {{ "/assets/images/raspberry_pi@3x.png" | relative_url }} 3x"  alt="Raspberry Pi">
-      <h2>CircuitPython libraries on single board computers</h2>
+      <h2>CircuitPython libraries on single-board computers</h2>
       <p>
-        Most CircuitPython libraries also work on <a href="/blinka">single board computers (SBCs)</a>, such as the Raspberry Pi.
+        Most CircuitPython libraries also work on <a href="/blinka">single-board computers (SBCs)</a>, such as the Raspberry Pi.
         Linux runs "desktop" Python (commonly known as CPython) instead of CircuitPython.
-        Our CPython Blinka library provides CircuitPython's low level hardware APIs, such as `digitalio`.
+        Our CPython Blinka library provides CircuitPython's low-level hardware APIs, such as `digitalio`.
       </p>
       <p>
         Blinka and CircuitPython libraries are just a `pip install` away.
@@ -172,7 +172,7 @@ <h2>Just the beginning...</h2>
     <p>
       CircuitPython continues to evolve, and is constantly being updated. We
       welcome and encourage feedback from the community, and we incorporate this
-      into how we are developing CircuitPython. That's the core of the open source
+      into how we are developing CircuitPython. That's the core of the open-source
       concept. This makes CircuitPython better for you and everyone who uses it!
     </p>
     <p>